1. Field of the Invention
The present invention broadly relates to a disk drive device for allowing recording of information onto and reproduction of information from a recording medium, such as a magnetic disk, and, more particularly, to a shutter opening-and-closing mechanism for opening and closing the shutter of a disk cartridge containing a disk.
2. Description of the Related Art
For example, a magnetic recording/reproducing apparatus for recording and/or reproducing information to and from a magnetic disk contained in a disk cartridge is constructed such that when a disk cartridge with a shutter is inserted in an opening in the front face of the apparatus, the shutter is opened, and when the disk cartridge is taken out from the opening, the shutter is closed.
A known conventional shutter opening-and-closing mechanism of the aforementioned type is disclosed, for example, in Japanese Patent Laid-Open No. 4-186555. The shutter opening-and-closing mechanism, which along with a pair of magnetic heads, is provided in the magnetic recording/reproducing apparatus. The shutter opening-and-closing pin is slidably mounted in a guide hole formed in the top surface of the holder, and is biased unidirectionally by a spring. The disk cartridge includes a hard-plastic cartridge case, a magnetic disk rotatably contained in the cartridge case, and a shutter which can reciprocate along one side edge of the cartridge case, with an opening formed in a portion of the cartridge case. The shutter is biased unidirectionally by a spring, and includes a cutout engagable with the shutter opening-and-closing pin, and a window formed in correspondence with the opening in the cartridge case.
While the disk cartridge is being inserted into the holder from the opening, the shutter opening-and-closing pin engages the cutout in the shutter, causing the pin to move within the guide hole against the tensile force of the spring. When the disk cartridge is pushed further into the holder, and the shutter opening-and-closing pin reaches the terminal end of the guide hole, the shutter opens completely. With the shutter completely opened, the magnetic disk exposed through the opening and the window moves into a location between the pair of magnetic heads, whereby the magnetic heads record information onto and/or reproduce information from the magnetic disk.
In the above-described conventional apparatus, however, when, for example, the disk cartridge is inserted into the holder with too much force, the shutter opening-and-closing pin may bounce off the shutter and disengage the cutout in the shutter. When the disk cartridge is further pushed into the holder, with the pin disengaged, the shutter opening-and-closing pin, moves in the guide hole, without being engaged in the cutout, causing the disk cartridge to be pushed into the holder, with its shutter closed. Thus, the magnetic heads hit the shutter, remaining closed, which may damage or scratch them.